1. Field of the Invention
The present invention relates to an inspection apparatus and an inspection method for acquiring information (physical properties, identification, concentration, presence, etc.) on a detection object using electromagnetic waves. In particular, the present invention relates to an inspection apparatus and an inspection method using electromagnetic waves of frequencies including at least a part of a frequency range of from 30 GHz to 30 THz (called “terahertz waves” in the present specification).
2. Description of the Related Art
In recent years, attention has been paid to a technique using terahertz waves with the development of a unit for generating and detecting the terahertz waves. For example, as an applied field of terahertz waves, there is a technique that conducts imaging using terahertz waves as a safe fluoroscopic inspection apparatus to replace X-rays. Also, researches and developments are made on a spectroscopic technique for inspecting an absorption spectrum or complex dielectric constant of a material to check a bonding state, a technique for analyzing a biologic molecule, and a communication technique.
Appl. Phys. Lett., 88, 212511, 2006 discloses an article related to a transmission line terahertz sensor in association with the above-mentioned technique. Reference numerals 104 to 108 in FIGS. 16A and 16B schematically illustrate a transmission line terahertz sensor of Appl. Phys. Lett., 88, 212511, 2006. In this example, a terahertz wave generation section 107 and a terahertz wave detection section 108 are integrated together on a substrate 104, a polyethylene vessel 105 is located so as to include those members therein, and a detection object is introduced from a detection object introduction hole 106.
Also, there is disclosed a technique in which a detection object is arranged in the vicinity of a transmission line with a periodicity of a certain wavelength order in a transmission line terahertz sensor (refer to Japanese Patent Application Laid-Open No. 2006-153852). In both techniques, the detection object is deposited on or in the vicinity of a transmission line. Then, electromagnetic waves that are propagated in a transmission line and the detection object interact with each other, to thereby operate as the transmission line terahertz sensor.